feat(i18n): tools + landing page + doorstop generator in English

Phase 1 of full English translation:
- generate_doorstop_items.py: all 55 items (SG/SYS/SWE/SA/SWA) rewritten in English
- generate_landing_page.py: full UI labels, KPI cards, section headings in English
- traceability.py: docstring, error messages, HTML headers in English
- generate_test_report.py: report content + table headers in English
- All 55 markdown items in safety/sg/, reqs/, arch/ regenerated in English

Still to come:
- demo-epb filled Word docs (PID, plans, safety, manuals, audit artefacts)
- Code comments + test names + CI workflow step names
- README + dev-process repo templates

arch/swe/SWA-003.md

@@ -15,13 +15,13 @@ asil: B
 
 # SWA-003: Actuator Driver
 
-## Verantwortung
+## Responsibility
 
-Low-Level-Ansteuerung der beiden Aktor-Motoren. PWM-Generierung,
-Strom-Messung, Overcurrent-Cutoff, Klemmkraft-Schaetzung.
-Implementiert in `src/actuator_driver.c`.
+Low-level control of the two actuator motors. PWM generation,
+current measurement, overcurrent cutoff, clamping-force estimation.
+Implemented in `src/actuator_driver.c`.
 
-## Statische Sicht
+## Static view
 
 ```plantuml
 @startuml
@@ -32,7 +32,7 @@ Implementiert in `src/actuator_driver.c`.
 @enduml
 ```
 
-## Schnittstellen (Provided)
+## Provided interfaces
 
 ```c
 Status actuator_init(void);
@@ -40,20 +40,20 @@ void   actuator_apply(ActuatorId id, uint8_t pwm_percent);
 void   actuator_release(ActuatorId id, uint8_t pwm_percent);
 void   actuator_stop(ActuatorId id);
 ActuatorStatus actuator_get_status(ActuatorId id);
-void   actuator_isr_1khz(void); // Strom-Sampling
+void   actuator_isr_1khz(void); // Current sampling
 ```
 
-## Ressourcen
+## Resources
 
 - Stack: <= 256 B
-- Worst-Case Timing: 50 us / ISR
-- Static RAM: 64 B pro Aktor
+- Worst-case timing: 50 us per ISR
+- Static RAM: 64 B per actuator
 
-## Mapping auf Anforderungen
+## Mapping to requirements
 
-| Anforderung | Wie abgedeckt |
-|-------------|---------------|
-| SWE-006 | actuator_release fuer beide Aktoren parallel |
+| Requirement | How covered |
+|-------------|-------------|
+| SWE-006 | actuator_release for both actuators in parallel |
 | SWE-013 | actuator_isr_1khz |
-| SWE-014 | Overcurrent-Detektor in ISR |
-| SWE-015 | Peak-Current-Tracking + lineare Klemmkraft-Schaetzung |
+| SWE-014 | overcurrent detector in ISR |
+| SWE-015 | peak-current tracking + linear clamping-force estimate |